Quilting is a special art in the general field of sewing in which patterns are stitched through a plurality of layers of material over a two dimensional area of the material. The multiple layers of material normally include at least three layers, one a woven primary or facing sheet that will have a decorative finished quality, one a usually woven backing sheet that may or may not be of a finished quality, and one or more internal layers of thick filler material, usually of randomly oriented fibers. The stitched patterns maintain the physical relationship of the layers of material to each other as well as provide ornamental qualities. In quilting, two different approaches are generally used.
Single needle quilters of the type illustrated and described in U.S. Pat. Nos. 5,640,916 and 5,685,250, and those patents cited and otherwise referred to therein are customarily used for the stitching of most comforters, some bedspreads and other products from pre-formed or pre-cut rectangular panels. Some single needle quilters are used to quilt patterns on fabric that carries a pre-woven or printed pattern, with the quilting adding to or enhancing the appearance of the pattern. Such quilters require that pre-patterned material be manually positioned in the quilting apparatus so that the quilting can be registered with the pre-applied pattern or a complicated visual positioning system be used. With such systems, border quilting or coarse pattern quilting can be achieved but high quality outline quilting around the pre-applied patterns or the quilting of pattern details of a fraction of an inch in scale are difficult to achieve, particularly automatically. Single needle quilters are usually lock stitch machines.
Large scale quilting operations have been used for many years in the production of bedding products. Mattress covers, which enclose and add padding to inner spring, foam or other resilient core structure, provide functional as well as ornamental features to a mattress. Mattress covers are typically made up of quilted top and bottom panels, which contribute to the support and comfort characteristics of a mattress, and an elongated side panel, which surrounds the periphery of the mattress to join the top and bottom panels around their edges to enclose the inner spring unit or other mattress interior.
Mattresses are made in a small variety of standard sizes and a much larger variety of combinations of interiors and covers to provide a wide range of support and comfort features and to cover a wide range of product prices. To provide variety of support and comfort requirements, the top and bottom panels of mattress covers are quilted using an assortment of fills and a selection of quilted patterns. To accommodate different mattress thicknesses, border panels of different widths are required with variations in the fill for border panels being less common. Border panels as well as top and bottom panels are usually made in different sizes to accommodate all of the standard mattress sizes.
Mattress covers are usually quilted on web-fed multi-needle quilters. Only one side of the quilted product need be finished for a mattress cover, so one layer of ornamental top goods or ticking is usually combined with fill and backing material to produce the mattress cover products on a chain stitch quilting machine which can use large spools of thread and quilt on webs of material supplied on rolls. Multiple needle quilters of the type illustrated in U.S. Pat. Nos. 5,154,130 and 5,544,599 are customarily used for the stitching of mattress covers, some bedspreads and other such products which are commonly formed from multi-layered web fed material. These multi-needle quilters include banks of mechanically ganged needles that sew multiple copies of a recurring pattern on the fabric. With such multi-needle machines, the combining of quilting with pre-applied printed or woven patterns in the fabric which would require registration of the quilting with the pre-applied patterns is usually not attempted. Multi-needle quilters are usually chain stitch machines. Such quilters include banks of mechanically ganged needles that sew multiple copies of a recurring pattern.
The ornamental characteristics of the ticking that form the outer surface of a mattress are regarded as important in the marketing of bedding products. Bedding manufacturers stock a variety of ticking materials of different colors and types, many having different sewn or printed patterns. Maintaining an adequate inventory of ticking requires the stocking of rolls of different widths of materials of different colors and patterns. The cost of such an inventory as well as the storage and handling of such an inventory contributes substantially to the manufacturing cost of bedding products.
Some of these quilted patterns are highly ornate and contribute materially to the appearance of the quilted products, particularly those that are of higher quality and cost, and which are made in smaller quantities. With such high-end products, the combining of quilting with pre-applied printed or woven patterns in the fabric may call for registration of the quilting with the pre-applied patterns, which is difficult to achieve with multi-needle machines. But other quilted products, such as those with simple zig-zag quilted patterns, are more functional, and rely on the varieties of the ticking material for the visual distinctiveness of the product. The varieties of ticking materials include those sewn or printed with different patterns. For such products, printed patterns are usually applied by the ticking supplier and rolls of ticking of each pattern are inventoried by the mattress cover manufacturer.
Other quilting machines and methods employing some of the characteristics of both single needle panel type quilters and web fed multi-needle quilters are disclosed in U.S. patent application Ser. No. 08/831,060 of Jeff Kaetterhenry, et al. filed Apr. 1, 1997 and entitled Web-fed Chain-stitch Single-needle Mattress Cover Quilter with Needle Deflection Compensation, now U.S. Pat. No. 5,832,849 and U.S. patent application Ser. No. 09/189,656 of Bondanza et al. , filed Nov. 10, 1998 and entitled Web-fed Chain-stitch Single-needle Mattress Cover Quilter with Needle Deflection Compensation, both hereby expressly incorporated by reference herein. Such a machine uses one or more separately controllable single needle heads that apply chain stitches to panels or webs.
The production of quilts by off-line processes, that is those involving both printing and quilting processes performed on different production lines, has included specialty product production involving the outlining or other coordinated stitching onto material on which patterns have been preprinted. Stitching in such processes is traditionally carried out with manually guided single needle quilting machines. Proposed automated systems using vision systems to follow a preprinted pattern or other schemes to automatically stitch on the preprinted material have been proposed but have not proven successful. Registration of pattern stitching with preprinted patterns has been a problem. While efforts to align printing and stitching longitudinally or transversely have been made, angular orientation of the printed web and the angular alignment printed patterns with the quilting head has been ignored. Correction for misalignment of quilted and printed patterns by repositioning of a quilting or printing head is inadequate if multi-needle quilters are to be used, particularly where angular mis-orientation is present.
Application of registration techniques to roll fed materials, where printing and quilting are performed on the material webs, presents additional problems. Registration errors that are minor where patterns are applied to individual panels produce cumulative errors when patterns are applied to webs. This is particularly true where angular orientation errors result due to skewing of the web as it is fed into the subsequent pattern applying machine after removed from a machine in which the first pattern has been applied.
With off-line processes for applying one pattern and then another in registration with the first, one by printing and one by quilting, production of quilts in small batches of pattern combinations is particularly a problem. Each batch can include one or a few quilted products of a common design made up of a printed pattern and a quilted pattern in combination, with the products of different batches, preferably to be consecutively made on the same machinery, being made up of a different printed pattern in combination with a different quilted pattern. As a result, the matching of the second pattern to be applied with the correct pre-applied pattern as the partially completed products are moved from a first machine or production line to a second is critical and a potential source of error as well as production delay.
For example, the outer layer of material used for mattress covers that is referred to as ticking is supplied in a variety of colors and preprinted or dyed patterns. Generally, mattress manufacturers who are the customers of the quilted mattress cover manufacturers or quilting machinery manufacturers require a wide variety of ticking material patterns to produce a variety of bedding products. Frequently, small quantities of each of the variety of products must be made to supply their customers' requirements, requiring the maintenance of inventories of a large number of different patterns of ticking material, which involves substantial cost. Further, the need to constantly match patterns as well as to change ticking supply rolls when manufacturing such a variety of products in small quantities can be a major factor in reducing the throughput of a mattress making process and delaying production. These and related problems continually exist in the manufacture of bedspreads, comforters and other quilted products where a variety of products in small quantities is desired.
Other off-line processes may involve the loading of rolls of ticking materials commonly bearing a pre-applied pattern onto the quilting machines. Lower cost mattresses are often made by sewing generic quilted patterns onto printed pattern material. However, frequent changing of the ticking material to produce products having a variety of appearances, requires interruption of the operation of the quilting machine for manual replacement and splicing of the material. This adds to labor costs and lowers equipment productivity. Further, the spliced area of the material web which must be cut from the quilted material is wasted. Furthermore, since mattress top and bottom panels are often thicker, and vary in thickness more than border panels, border panels are sometimes quilted on quilting lines that are separate from those used to quilt the top and bottom panels. Since border panels are usually preferred to match the top and bottom panels, the changing of ticking on the top and bottom panel line is almost always accompanied by a similar change of ticking material on the border panel line. Coordination of the two production lines, as well as the matching of border panels with the top and bottom panels, requires well executed control procedures and can lead to assembly errors or production delays.
There exists a need in mattress cover manufacturing for a capability of efficiently producing small quantities of quilted fabric such as mattress covers, comforters, bedspreads and the like where different pre-applied patterns on the product are desired to be enhanced by combining the pre-applied and quilted patterns, particularly where combinations of quilted patterns and printed or other pre-applied patterns must vary with each or every few products. Further, there is a need in mattress cover manufacturing to improve the productivity and efficiency of making quilted products, particularly mattress covers, having a variety of designs without increasing, or while reducing, production costs.